Typical PMS is around 2,000+... can't remember exactly, pero under 2,500. That's at the casa. Outside is cheaper, definitely.
Medyo mahal yung alignment and brake work dahil 440 per hour ang labor (easy to just do this outside nalang). Mahal din ang suspension parts, so it's easier to get outside. Take note, iba yung shocks at springs ng RS sa typical na Lynx, so if you ever need to replace them, might as well get a full set of H&R (costs only a bit more than a full set at the casa).
If there are any problems regarding sensors, sensors for any Ford typically cost under 5,000 (even for Expeditions) so it's not painful to fix despite horror stories from some 2001 Lynx 1.6 owners. Pero since two years old or less yung mga RS, you won't need to think about this for a long time. Anyway, no reported sensor problems for the 2.0 yet.
Engine accessories are an unknown, but any possible problems will be just as cheap/expensive as with any 1.6 - 2.0 compact car.
450 is good if that's a 2003 unit... I'd have expected the price to be around 495 at 40% depreciation, but the market for secondhand Ford Lynxes is very thin, so take advantage of it if you really want it.
If the RS is modified, check how well the engine runs. Aside from Oyo boy's unit, there are rumors of another RS that had a blown engine because the owner overboosted it with a turbo. Better to get an RS with all stock or Intake-Headers-Exhaust mods only. Also, better check for accident damage... medyo mabilis kasi mag-drive ang mga RS owners, eh. :lol: