You have a good point as everyone will tell you to buy it whatever. The fact is you have a cheap place to live and so what if you can make some money on top?
If you really really have to buy it you either need more income/take in a lodger/get extra money out to subsidise the cost of the mortgage (but this will run out). Work out how long the �66,000 will take to run out if you buy the house and see if it really is worthwhile. You could end up with a liability. Why not wait to see if the market crashes? I'm sure you won't lose anything. If the scheme allowing you to buy the house is to be withdrawn you will I am sure be given notice of this. Best of luck.