if we do a collective sale

I spot this piece of land, currently there're 4 semi-D houses, all are very old. If we can collectively buy over the 4 semi-d, and re-build:


to buy over, estimate 6.5Million each x 4 =  26Million
stamp duty: 26m*3% - 5.4K = 0.7746Million
to rebuild(including interior): estimate 1million x 4 = 4Million

Estimate rental per year: 18k per month x 10month x 4 = 0.72Million

Estimate selling price in 4 Years: 9million x 4 = 36Million
cost for marketing/sales 2% * 36Million = 0.72Million

Investment: 26+0.7746+4 = 31 Million
Rental Return Yeild: 0.72/31 = 2.3% ( 1st year under construction, there'll be no rental return)
4 Years capital gain: (36 - 31- 1) /31 = 12.9%
Yearly appreciation based on 12.9% = 1.89%

Well, better than put money in the bank, but still not so attractive leh.