I am sorry that you have had this experience.
You don't indicate in your post as to the damage incurred so I'll assume a worst case scenario.
As well as your blown head gasket, it's likely that the engine head may be warped requiring work.
Having had the challenge myself, it was a week without the vehicle and AUD$1500 removed from my petulant wallet. :crying: You, however, may very well get away with repairs for less than I had to pay...so don't panic unnecessarily.
My event was caused by the top tank parting company from the radiator which combined with slight inattentiveness led to catastrophic failure.
You may save some money by pulling the head yourself, if you are apt, sending it for reconditioning and then rebuilding everything when you get it back. Takes time and constant enquiry from SWMBO as to "how much longer is it going to be...?"More cost effective to let a mechanic earn a few dollars for the time, skinned knuckles(and earache! :grin: ) it will save you.
If you don't already know what caused the gasket to go, then I would investigate to determine that as well.
If your beast has given 198000kms of reasonably trouble free driving and has no other problems, then there may be cause to keep it, if it is up to scratch otherwise.
Mine now has over 250000kms onboard, of course not without expense for repairs and maintenance, and I have tested the rev limiter more than once in those kms :blush:. On balance, I would say that it has given more than a fair accounting of itself.
Any vehicle is going to require maintenance to keep going, even new ones. Find a good mechanic and get an honest appraisal about your vehicle. Find out if it's worth repairing. Unless it's a basket case, it should be OK.
Hope this is useful.