Does the exchange rate at the time of the transaction matter in this?

As far as purchases I now regret ...

I still have unspent a Starbux $10 gift card that I purchased with bitcoins, paying 50 BTC for it (back when they were trading at under $0.25 per BTC).

There are a few people who paid for ASIC hardware back when BTC/USD was about $6 and are still waiting, with regrets.