Also, is this you first time having a 1 year working visa? If that is the case, they will give you a month Visa (under observation) before they give you the full 1 year.
You can leave the country but be sure to return before that 1 month visa expires.
In some cases, the immigration from your ciuntry will be yhe one who will ask for you work permit. (Again, in some cases) this is to prove that you are really working here in Thailand.
My suggestiom is, go straight to the labor dept. Once you get your Visa. The process will just take 1-2 (business) days.
somehow I disagree with your statement "it's all about the MONEY".
Lately there have been a lot of cromes that involve foreigners who wntered Thailand illegally or those who are abusing the Border bounce.
I do understand that Thailand still has corruption but please consider that Thailand is doing it's best for its people's safety, including expats living here.