I once did the math. Refinancing from high interest to low interest or refinancing low interest to high interest will cost you the same amount in interest over 30 years assuming identical house prices. However during times of low interest house prices are higher than during times of high interest and this means if you get a mortgage with high interest you end up paying less overall for the house but a bigger portion of your payments are used to service interest.

Therefore the 15% house is the best deal.

>closer to town, larger, better schools, You're shifting goal posts now. Buying a more expensive house doesn't get you any of that. Only buying more expensive land does.