I came here to share my latest experience.
My personnal situation (job seeker) made me think about the kind of visa I should take to stay a bit longer.
Just to note that I'm here for one year and a half and has been on non resident B for one year and then tourist visa until now (with few overstays...).
The cost of a new visa run made me think a bit more about what I should do to stay longer.
I heard about some people flying out to Malaysia and come back on the next flight.
So I decided to make my own experience.
I checked the flights tickets and the cheapests (in the Songkran period) was to Siem Reap: 4000 THB return ticket.
I checked again if anyone has done this in the past, on internet, I haven't had any information...
While I booked the ticket I saw a note saying that I would have to stay for a night before I was going back to Thailand but no problem, that was my plan anyway.
One thing I forgot was that, if you want to go to cambodia, you must pay a 30 $ visa (plus an extra 2$ if you don't have any ID photo on you) even for one day....
Plus the one night stay in a guest house (5$ a night in a dorm, much enough for me), the taxi from the airport and going back (12$ in total), few beers and food (5-6$).
On the way back, I was a bit under pressure that the thai immigration won't let me in (my passport is full of thai/lao/myanmar/cambodian visas and stamps...) but at the end there were no problem.
So it is possible!
Total cost: 6000 thb (songkran period and with cambodian visa) a bit too expensive compare to a visa run (2 month)
Also: that way is not exhausting at all (taxis and flights only). Compare to the visa runs (transport in van/queuing under the sun outside...)
Maybe it would be interesting to see on an other period (out of songkran), and see if there's a cheaper visa that the Cambodian around.