I have more regret invested in instruments I missed out on buying in the first place than I do on those I have sold.
Re the “dibs” nonsense, I have never subscribed or agreed to the idea of a seller retaining some kind of option-based interest in anything they have sold, whereby the buyer is compelled to contact them if he/she intends to sell it on. If someone approaches me with a spectacular part exchange, or offer for a bass I have bought do I turn it down to avoid upsetting the former keeper?
Upsetting the previous owner is an issue for the seller, not the buyer, if there is an agreement. That said, if you sell something, accept that it is gone.
