Electronics, like your TVs, you can look at probably double the price in the States (I'm familiar with those prices is why I quote them).
With apartments, there are two types of rental - temporary (not longer contract than 6 months legally) and 2 year leases (the norm for residents). Lack of a more permanent visa is not a problem for either of those.
The temporary apartments will require the money up front. It's just the way it is. I have never heard of anyone renting a temporary apartment on making payments as you go.
However, you can sign a two month agreement, and tell the owner that you want to reserve the following two months, and then write a new contract and go on that way, paying the length of the contract. You have to talk to the owner up front so that they don't schedule someone else in there. Temporary apartments here are often in demand, particularly in the summer when more tourists come.
Some owners may only let you occupy their apartment for 6 months, no matter the term of the actual contracts. People are VERY untrusting here to people occupying their apartments because the laws are so against the owners and for the occupants that it is very hard to get someone out of ana partment, particularly if they have been there for more than 6 months.
In fact, you have to normally have property to use as a gaurantee to rent an apartment for a long term lease.
It's possible to find an apartment somewhere that is being rented directly by an owner, and they may make some kind of deal with you related to being able to rent on a more permanent basis, but it takes time to make contacts and get all that worked out.
As far as the visa goes, you can probably figure out some way to get it to work, but I would not suggest doing something that is not a no-brainer (like having a work contract or being married to a resident) by yourself.
I've made a recomendation in a couple of places for a lawyer that I use and is extremely knowledgeable and trustworthy and charges low fixed rates.
As far as dating an Argentina - I know what you're talking about as far as dating just about anyone in Thailand because you're a foreigner, rich (in relation to them certianly) and they have a hope of something more permanent that could elad to a big change for them.
You won't see that kind of attitude here. Argentinas aren't looking for a foreigner to "take them away" from their world. It's more of a normal dating process and you will probably have to spend some time to get to know people and such. Can't speak to one night stands though...
As far as the food - well, everyone has their own opinion. To me, the food here is very bland and unimaginative for the most part. There are exceptions to that, but be ready to eat Parilla, Pizza and Pasta normally. In fact, the Argentine food is usually without much spice - if you put a little bit iof black pepper on food they eat, they may be fanning their mouth with the picante it gives them.
I am from Texas, where we like things hotter and spicier, so maybe a lot of this is just me, but most of my friends here agree with the food comments.