Car was £1300 but are valed 2500. Yes first car

Unfortunately the engine will need stripping down to assess the damage before they can estimate what repairs are needed. That will cost whatever hourly rate they charge.

 

Taking off timing cover to see if chain is snapped or jumped, then possibly remove spark plugs and examine cylinders/pistons/valves with a borescope. Depending on that examination then whether to proceed to remove cylinder head. 

 

Typically it would require a complete head refurbish, or replacement head and new chain and sprockets. At least £1000, probably considerably more.

 

And remember its already done 90k and if the chain failed, that indicates oil/filter weren't done regularly or correctly, despite what Skoda or old lady says.

 

Take it a step at a time, ask a trusted independent garage (don't bother with Skoda, they'll be mega expensive) to check chain first and ask if they can do a borescope check on the valves and pistons. Then consider whether to proceed or go to scrap or if you can break it for spares and sell on ebay, worth more that way.

If i look to replace the engine should i go for a bare engine or a complete one ?

Best that you get nothing, but find a trusted garage or mechanic that diagnosis the faults, and then if replacing the engine is required has the contact in the trade to source an engine they feel can be installed and will not be as bad as the one being replaced.

 

Trust the professional, but only ones that you can get recommended to trust by trusted friends or people.

Follow Offski's advice.