Re: 156 2001 engine gubbed
best option is to find out where the oil is leaking from, then you know what the cost will be. could be headgasket, piston ring or valve guide, repair costs will vary widely depending on where you go and what the cause is. i wouldnt recommend a different engine unless you really need to, you never know what you're getting when you buy a used engine so its always a bit of a lottery.
do a compression test, dry first, then wet, that will tell you if its the piston ring (pressure increase when wet) or not.