Time in the market beats timing the market. If you really have your heart set on Boston and can afford to buy now, you should just go outside the metro area until you can find something you can afford and buy. Build up that equity, then if the situation improves in Boston, cash out the equity and buy in Boston. If not, stay where you are.

If you're ready to buy now and keep waiting, you're going to lose in the end with inflation eating away at that down payment.