i am getting frustrated searching online as I cannot find anything in this size range. i have been on many sites and have only found a handful of listings under 1000-1500 ft2...

i want to spend about 300.000 USD and would appreciate suggestions.

I'd like to point out a couple of things about Macau...
1. Area is based on gross area (like HK, China, but not anywhere else in world). This includes lobbies, lifts, club house etc so efficiency (ie how much area your unit has is around 70% (or even less esp for latest developments). Additionally, bay windows are counted under net areas, so a 700 sf flat (70sm) is likely only 450-500 sf.
2. Area large compared to HK standards. This may be due to the days when land was cheap. So a 3 bed may be 1200 sf where it can be 900 sf in HK.
3. In new developments, developers probably focussing on luxury market (or claiming) due to higher margins in a rising market.

For that size, I know offhand that you can get studio, 1 bed in 1 Central residences, Tower 1. These are smaller units. This should be in your range. I think there is another under development Cotai Strip No 1. Both are new (hence expensive).
Regarding existing units, I'm afraid don't know about that.

Wow, that is very confusing and unusual way to list the size of the apartment. Thank you for pointing that out.

So the units at 1 Central Residences and Contai Strip No.1 which are in my price range of 300k usd.. what is the actually size without counting the lift,lobby,etc

As an example, here's some actual figures...
Tower 1
One Central Studio (flat D): 654 sf (gross), 510 sf (saleable area), 43 sf bay windows.
One Central 1 Bed (flat C - 10-21/F): 895 sf (gross), 698 sf (saleable), 46 sf bay windows.
One Central 1 Bed (flat C - 22-29/F): 918 sf (gross), 716 sf (saleable), 46 sf bay windows.
One Central 2 Bed (flat B - 10-27/F): 1359 sf (gross), 1060 sf (saleable), 74 sf bay windows
see www.onecentral.com.mo

Approx. definitions.
Gross area = Saleable + common areas
Saleable = net area + internal walls

So actual, 'useable' area = saleable - bay windows - walls
So for studio, 654sf gross gives 510 sf saleable, 467sf excluding bay windows, and maybe 430-445sf if you include internal walls (this not listed). Just to complicate it further, in some cases, air-conditioning ledges may be included in area, and you can also consider balconies !!

Normally efficiency is saleable/gross, so in this case (78%). But in actual fact, if you maybe take out internal walls, bay windows, efficiency may be 65%. I think in some extreme cases, this could go as low as 50% (eg including roof/car parks), so you could get almost half the area you purchased on a gross basis. This is basically a ploy by developers to give you a 'cheap' psf price.

I think in most other places (eg Thailand, Malaysia, Singapore) area is saleable area. You will have less after deducting air-con ledges and internal walls, so you are likely to get 85-90%. I think this figure is approx 70% for HK/Macau. This figure becomes less the bigger the clubhouse/facilities.

Unfortunately prices in Macau have shot up in past few year, so for USD300k (approx HKD/MOP2.4m), so you are unlikely to get this for upper/luxury new developments. E.g. One Central studio cheapest price (10/F) was sold at HKD2.75m (or less with discount), and approx $3m for mid floor. The mid floor units now likely at around $5m (USD640k). However, note for this you need to pay $3m cash upfront as mortgage not available until unit has been completed (I don't think banks will lend).
It may be possible to get some almost new units for your budget at around $2.5k psf in Nova City (havent got floor plans, but say you can buy say 1000 sf gross, maybe 3 bed for below $3m).
For 10-20 year old property, prices are still in $1-2k psf range.

654 ft2 x .7 = 458 ft2 = 43 m2

640K USD/43 m2 = 14.9KUSD/m2

Ouch. Looks like you guys are doing quite well. I wish I had some to Macau a couple of years earlier.

"1000 sf gross, maybe 3 bed"

1000x.7=700ft2=65m2... how can you have 3 bed on only 65m2, do you mean 3 rooms? like one bedroom to sleep, one living room and one kitcheen? thanks.

654 ft2 x .7 = 458 ft2 = 43 m2

640K USD/43 m2 = 14.9KUSD/m2

Ouch. Looks like you guys are doing quite well. I wish I had some to Macau a couple of years earlier.

"1000 sf gross, maybe 3 bed"

1000x.7=700ft2=65m2... how can you have 3 bed on only 65m2, do you mean 3 rooms? like one bedroom to sleep, one living room and one kitcheen? thanks.

I say 'maybe' 3 bed. In HK, 1000sf is more than enough for 3 bed, I think they can squeeze this into 850sf in some projects !!. As mentioned, Macau is 'bigger' so 800-1100sf is normally 2 beds.

Given how house prices are moving, I believe eventually developers will be squeezing more in. Remember, Macau is apparently size of HK Airport !!

Nongice, I think you are from Thailand... where prices are one of the cheapest in Asia. In HK (and maybe big China cities, and soon Macau), people are used to small areas... Agree, Macau is not cheap anymore even compared internationally..., and I think Macau wants to be recognised as one the 'global' cities in the future (at least Asian destination).. hence the potential to come closer to HK/SG levels. I think after the price hikes, Macau is now a bit more expensive than Shenzhen, but not unreasonably so for mainland Chinese, and prices are I think on a par with top KL developts, in Malaysia. In addition its GDP/capita is the highest in Asia, more than Japan and 20% more than HK.