Visa runs to Cambodia cost around 4000. Don't pay the high prices some agents are asking for, they are all offering the exact same service at different prices.
But you should just fly to Kuala Lumpur and have a weekend holiday instead of sitting in a van all day for a new stamp.
they are exactly that. Always posted by profiles with photos of light skinned skinny women, because that's what works for scamming Thais and old white men.
You have to physically be at a training facility for 15 hours to get your license, legally.
Anonymous participant you have 5 years to activate your visa by entering the country. But no embassy is going to give you a visa further then 3 months out from your trip.