Just a heads up: you will need to show proof of accomodation (where you'll stay in BKK, even if it's just for the first few nights), and proof of onward travel (your transportation date and mode out of Thailand).
Traveling visa trouble. There's so much info out there that is frequently changing.
Bought a ticket to Saigon from BKK. Showed up at the airport and was asked for my entry visa to Vietnam. I had read that I could get visa on arrival, but this was not correct.
I had to scrap that trip and went to Vientiane instead. Same day ticket, since my visa was expiring, so it was not cheap.
Do research from official government websites, or chat with a travel agent. Don't trust the mountains of misinformation on the internet.
overstay is only 500baht per day, so if op is only staying 2 days over, it would actually be cheaper than extending. But yes, op would probably be barred from returning for a year.
if you use Airbnb (there are hostels on there too), they give discounts for booking a month or more at a time. Sometimes those discounts are around half the normal price!
I usually can find a studio or 1br with full bath for $300-500/month, but I've seen hostels as cheap as $160/month. Keep in mind that's only when booking for a month and I usually book about a month in advance of the dates I'm looking for.
I just hit the 6 month mark on tourist visas and border runs. Spent at least a week in Laos and Cambodia to actually experience the countries on those runs.
I'm about to go back to Bangkok and get an education visa. 1 year is about $1000 for Thai language lessons. 2hrs a day 4 days per week, with option of remote classes.
Probably one of the safest bets.
Or you could TRY to do 4-6 border runs (4 runs if you do 60 days + extension, 6 if you do 30 days + extension) to get your year in Thailand on tourist visa, but that's playing with fire these days.