I think it all depends on what one considers "Bitcoin dust"... For most, this could be < 0.001 BTC. For many it could be < 0.1 BTC, and for some it could be < 1 BTC or even < 10 BTC...
Usually, the term "dust' is used for inputs that lower than (or close to) the fee it takes to send them.
I take it that's not the definition you're using

Yes, I did use the term "Bitcoin dust" quite liberally. Perhaps, a more appropriate term would be "change" or "pennies" or any amount one does not care much about, in comparison with their main stash.
The few things I regret are some small (at the time) purchases using BTC, which are now worth thousands of USD.
Looking back, I've spent a small fortune on daily items. But I like to think of it this way: the more expensive those expenses get, the more my hodlings increase in value. So I've supported the Bitcoin economy while actually using it as electronic money, and I'm still better off because of the increase.
Every time I say that I regret using BTC for purchases, I can't help but feel like I'm somehow "betraying" Bitcoin by not supporting its use as money. Laszlo Hanyecz comes to mind. At the same time, Bitcoin has become so important and so valuable as an asset, that spending it on petty purchases just doesn't feel right anymore. It's like cutting a piece of gold to pay for your weekly supermarket shopping. I'd rather use fiat for that. Perhaps, there may come a time when the mere ownership (and not the spending) of Bitcoin will grant the owner special privileges. Bitcoin is just too precious to spend, unless absolutely necessary.