We have an account at Santander Rio. The fees for a Caja de Ahorro last year were 30 pesos a month (probably have gone up by now! but I don't know.) and I don't remember there needed to be a minimum balance kept in the account as long as you kept paying the fees. For us as residents, it was all we could open - I'm pretty sure it's the same for citizens as well.
We got a debit card (Visa) that you could use for store purchases, but it didn't work online at all.
After a time of good standing with the bank (can't remember if it was 6 months or a year) we were issued an Amex credit card that worked as expected. Pay the balance every month or roll the balance over into a high-interest loan (24% if I remember correctly - never used that option).
After 18 months, we were offered an actual checking account (Infinity is the product name - checks and everything) that came with a real Visa debit card, a line of credit up to 18000 pesos and personal loans up to 50000 pesos (I think that's the limit - it may be higher, or I may be thinking of another product - we have the lowest product available). The cost is 130 pesos a month.
If you open a Caja de Ahorro, you immediately get the ability to take advantage of special discounts that most stores give to bank members. You have to look around to see, but there are discounts as much as 25% on purchases. You also get the ability to buy on interest-free payments from most stores. I think all the major banks have their own set of discounts.
If you are going to live here a while, I'd definitely say it's worth getting - but you need residency. I don't remember if you've said you have or not. I've heard anecdotal cases of people getting accounts without residency, but I've never known anyone personally who managed it, unless it was tied in with their application for residency.
Don't plan on bringing money from outside directly into your account - it's possible, but you have to have everything in order and go through a lot of rigamarole to do it.
I get my money in through other means and deposit a portion in our bank account to take advantage of sales and other things. Be careful of the amount of money you deposit and run through the account - supposedly AFIP is notified of movement over a certain amount (I believe it's 3000 pesos, but not sure).
If you are going to be running a (relatively) lot of money through your account - think also about getting a monotributista situation set up to pay taxes. They are fixed, you can invoice an entity outside of the country and account for your money in that fashion. You cannot run more than 200K pesos through the system as a monotributista, but that allows you to be legal and not have AFIP hassles to that point.
Of course, at 200K monotributista, you pay $1857 in taxes a month - but that ain't a bad rate at 11% and covers your obra social and such.
144K a year in reported income, btw, is only $957 a month, or 8%.
There are some complications on Monotributista related to monthly reporting of income, the amount of income declared each month can determine your year-end status if it's not consistent and could end up putting you in a new higher level and owe back taxes, etc.