Bought a new TH but builder dropped price for 100K to 170K within three months

Me and my husband purchased a manufactured TH in SF Bay Area in July 2020. The townhouse is in a small community. After we purchase three months, the builder sell other similar THs with price lower 100K to 170K. This is really ridiculous and we feel bad about it. We have contacted the builder but they said the market changes and price changes. But we all know 2020-2021 house price goes high and the price drop is just too much.

If anyone know anything we can do, please help with some advises. Thanks in advance!

Townhouses and condos dropped actually very hard in 2020, due to covid-19. In some areas more than 15% in 2020 alone.

The trend has reversed since February 2021 (in the areas that I observe) and I see now sales at new all time highs.

Chances are that yes, you paid 100k more than someone in the second half of 2020, but right now, those units may be going 50k higher than what you paid.