Around here a sub 3k X5 is salvage territory. Assuming the worst and you pay 3k to have a good used engine put it you'd still be under the average cost for a good condition E53 around here.

I wouldn't expect any car for just a couple a grand to be anywhere near reliable. At that price the previous owner is just giving shit away really, meaning it's probably falling apart.

You can easily find a running m54b30 locally for under a grand as BMW used them in pretty much everything. Swap the oil pan over and you should be good to go.

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03 3.0i mt
89 325is