2002 Vauxhall Omega engine misfiring

Engine Mechanical problem
2002 Vauxhall Omega 4 cyl 80000 miles

Hi there, I am considering purchasing a 2002 Vauxhall Omega 2.2 CDX off a motor trader in Hampshire.
The seller has stated that the engine is currently misfiring.
Although he has taken this into account with his asking price, I am obviously a little concerned.
Apart from the misfire, the car is described as being in excellent condition inside and out.
Seller has invited any inspections on the car at their premises, and states they have a ramp which can be used if required for a more in depth inspection.
Any advice or general comments about the misfire are very much appreciated.
Thanks for your time.
David.