That's a good question but really hard to answer. What condition is the
rest of the truck in ?  How much is the repair going to cost ? Can you
purchase another vehicle for the price of the repair ?

 If the truck is in good condition and well maintained it may be a good
idea to have it repaired. While you are doing the timing chain and cover
remove the cylinder head and have a valve job done. It might be a pricy
repair but you shouldn't have any more engine problems.

Depending on the cost of repair you may be able to purchase another vehicle
for less money. If you purchase another vehicle it may need just as much
work as the one you have now. Then you would be out the money for a second
vehicle and repair costs.

I did six 22RE headgaskets last year.
On my trucks and a few friends.
Every time I did the headgasket I went ahead and replaced the timing
chain cover, timing chain set, oil pump, and water pump.
All 4 of those together cost around $125 from the eBay parts dealers.

If the hole dumped your coolant into your oil pan then the engine will
need to be flushed before it can be used.
You might as well do the headgasket, and the rest.

Doing your own rebuild isn't that hard, and will end up around $500 in
parts.
It does however take quite a bit of time, quite a list of tools, a bit
of shop space to lay out the parts, and you really should get a factory
manual for your truck.

A reman  engine can cost from $1000 to $1800, depending on who you get
it from.
You can also opt for a Japanese crate engine known as the 21RU.
They cost around $600 and bolt right in.
They have a little less power, but they do work.

Toyota trucks routinely get 250,000 to 300,000 miles before the first
headgasket blows or the timing chain goes out.
After a rebuild you are looking at around 80,000 to 100,000 miles before
it goes again.

The best consistent engine pricing I have seen is from a eBay dealer
from Oregon.

I had my timing chain replaced at 125k as a precautionary matter.  It cost
about $1500 to have the shop replace it.  The truck still runs great at 150k
and I have no plans to get rid of it.  In fact I have had people at the
dealership offer to buy it.

I replaced the timing chain, guides, and tensioner on my 22re engine
last summer without pulling the head or oil pan. Mine hadn't worn into
the front cover yet but was starting to make noise at 215,000 miles. I
bought the parts from an eBay store for about $60 which included the
metal guides instead of plastic. I saw new front covers on eBay for
under $100 also. The job was a piece of cake and took me just a few hours.

Q