5 months x 30 days = 150 days x 20/day = Bs. 3000 x 5 people = Bs. 15,000 so you're looking at about $2152 in fines.
One year residency for 5 people will run you about $1800.
As long as you are not traveling or moving around much, I would say just pay the fine. But, the risk you are running is that you can be asked to show your documents at any time, anywhere, even if you are not traveling. The police in Bolivia DO have the authority to stop anyone at any time for any reason, or completely without any reason, on the street and request they show their documents. Not trying to frighten you, just think you should know.
On the other hand, getting residency for 5 people will likely take 2 months, but will cost a few hundred dollars less than the fine(s) you are likely to pay.
Tough decision. I think, being that I am also a parent, I wouldn't want to take the risk. I'd probably opt for safe better than sorry and get the residency.
If you felt overstaying illegally was a safe option, and you were not worried about it, you wouldn't be asking this question in the first place, so my guess is you're not convinced overstaying is a good option.
Mar 28, 2014 Rating
Thanks by: Anonymous
Very much appreciate your input on this. Super helpful.
Mar 27, 2014 Rating
No max. fine by: Alex
As mentioned below, there is no maximum fine. I've known dozens of people that have had to pay, and nobody mentioned anything close to the sort.
Don't forget, tourist visas cannot be renewed. If you try to do a "border run" and jump over to Perú for a day, you will NOT be allowed back into Bolivia if your visa is expired.
Best of luck.
Mar 27, 2014 Rating
And another follow up question! by: Anonymous
One person commented "Apparently max fine is 500 Bs". Can you say anything more about that? (or suggestions for where can I get more info on that?) That's less than a month over staying at 20 bs per day, so considerably less than i was imagining we'd have to pay for an extra 5 months. Which is good news, I suppose, but i'm interested in this because mainly I care about not getting into trouble either while still in country or while trying to leave! Thanks again to all for entertaining these questions.
Mar 27, 2014 Rating
No maximum fine by: Alex
There is NO maximum fine. I paid a solid U.S. $400 for overstaying, and know people who have paid U.S. $600 and upwards.
The most amount of trouble you'll likely get into is some more fines. I wouldn't be surprised if you're asked at the airport for your documents. But don't worry about deportation/jail anything serious like that.
Mar 27, 2014 Rating
Thanks and further question by: Anonymous
This is helpful (additional opinions welcome, too), thank you kindly. Another question then: If we 5 people are here those 5 additional months overstaying our tourist visa, what are the odds we get into trouble? (And what kind of trouble??) Mostly we are staying in one town, but we do intend to travel a bit around the country, once by flight to La Paz, mostly by taxi, hotels a couple times. All opinions warmly welcomed. Thanks again.
Mar 27, 2014 Rating
Overstaying visa by: Anonymous
The fine will be 20bs per day that you have stayed over the 90 day allowance, that is per person.
The maximum fine is apparently 500bs
Mar 27, 2014 Rating
No extensions by: Alex
You're in a pretty tough spot.
Your best bet is to just pay the fine.
Tourist Visas cannot be extended. Anybody who intends to get an extension for residency or any other purposes must enter the country on an Objeto Determinado visa.