Buying in two years could mean your $450,000 house becomes a $520,000 house. That’s only two years of 7.5% appreciation. It also would mean when you do buy, the house you want to live in for life will have a higher property tax valuation locked in forever, and you be paying an extra $760 a year in taxes forever. Actually more since they go up 2% a year.
You also may have to pay higher rates. But if rates end up going down a lot, you can refinance.
I also don’t know where your $15,000 closing cost estimate comes from, that’s more than three times the normal amount.