Summer of 2023 I went to Eastern Music Festival. I got a pretty substantial scholarship, but since I had to fly there with a bass from the west coast that kind of cancelled that out. Think I wound up paying something like 4-5k including flights.
This summer, I mainly auditioned for free festivals and didn't get accepted (got waitlisted). I recently bought a new instrument so my finances are fairly tight, which is why I couldn't go to EMF again, or a few others. I took some regional orchestra auditions and made sublists and I have some pretty good gigs this summer, along with my current regional orchestra job's summer concerts. I'm pretty happy with how it's worked out.
There's some really terrific advice in this thread from people much more experienced than me. My two cents... sometimes it's better to just practice over the summer. I took a hard look at my playing after those two pro auditions and realized I didn't get the results I wanted largely because my fundamentals need work, so I'm taking this summer to really drill my fundamentals in.