You have to determine whether you really want a crossfire then set a budget. Be prepared to spend as much on repairs and maintenance as you would be paying for this car itself. You can send the RCM to a forum member from Arizona who will refurbish it four around $50 currently. If the calipers and lines are good then brakes should not be a problem. There are drilled and slotted rotor kits with ceramic pads Between 250 and $400 for all four wheels or you might be able to have your rotors resurfaced and just get a good set of pads. I would recommend flushing all fluids and replacing all filters. Consider the condition of the tires and the cost of replacing them. You would definitely want to hear the engine run if at all possible. Make sure that all the electronics and air conditioning work. Last fall we bought a 2004 Limited coupe with 36,000 miles for $4200 and have since probably spent $2000 getting it back into the condition we wanted it to be. This car has 12 spark plugs and getting a good replacement set of NGK iridium nine plugs will run you at least $75. With 124,000 miles you’ll probably want to do the spark plugs, transmission filter, fuel filter etc. if the car is otherwise in very good condition it could be worth it and you would end up with a very nice ride after performing repairs and maintenance but there are also some very nice low mileage crossfires out there four between $7000 and $9000 from original owners who may have complete service records. It is usually best to start off with the nicest example you can afford but if the initial cost is low enough and you can perform a lot of the work yourself there are bargains to be found. Another option would be sending it to Josh at the Mercedes swap shop to have a V-8 installed. From what I’ve seen and read you can have it done for $6000 including parts or $3000 if you supply the engine and necessary parts. A nice option if the car you start with is cheap enough and in good enough condition to be worth the investment.