Whatever you pick, book the first three nights and leave the rest loose if the destination allows it. Alone you can change plans at zero social cost, which is genuinely the best thing about solo travel and the thing people give away by over-booking.
A cooking class or a food tour early in a trip solves this sideways. You spend three hours with people, you learn what to order, and you often end up with dinner plans for the next two nights. Best money I spend on any solo trip.
Hostels with a kitchen, even if you book a private room. Cooking in a shared kitchen at 7pm produces low-stakes conversation with zero effort, and you can leave whenever you want. It's the most reliable social hack I know.
One more angle: if your feet are at all unusual, the 300 pound pair is a bigger gamble because you've concentrated the whole budget into one fit decision. Two pairs is also diversification against buying the wrong last.
One practical thing: stop using fabric softener if you are. It coats the fibres and makes cotton limp over time, and oxford cloth shows it faster than anything else. White vinegar in the rinse does the softening job without the coating.