It's a shame it's too late to make class suggestions as this character's ripe for factotum (Du 14-20). More levels of wizard would really be a boon, too. She's already a wizard, so she's a conjuration specialist who took the alternative class feature abrupt jaunt (PH2 70), right? And since you don't care about her being especially effective, taking Mnk1 and beating up a sparring dummy of the master (AE 137) (30,000 gp; 40 lbs.) to get that 10 ft. of movement required for to use skirmish is kind of a thing. Anyway.

Obscure Feats

• The uncategorized feat Hardened Criminal (City of Stormreach 95) grants the creature immunity to attempts to Intimidate it and the ability to take 10 on 1 skill picked when the feat's picked. Note: This feat sprang to mind immediately when you mentioned your character's focus on the Escape Artist skill.
• The fighter, general, and Chult and wild dwarf regional feat Disentangler (Rac 162) grants the creature a +2 bonus to Escape Artist skill checks and a +2 bonus to opposed grapple checks.
• The general feat Daredevil Athlete (CS 76) as an immediate action 3/day grants the creature a +5 competence bonus to a single Balance, Climb, Escape Artist, Jump, Ride, Swim, or Tumble check. I assume the intent is the next one, though. As a competence bonus, it'll stack with the circumstance bonus from masterwork tools but not the competence bonus that often comes from magic items, which is sad.

• The aberrant feat Mourning Mutate (Dragon #359 110) as one of its benefits grants the creature a +3 racial bonus to Escape Artist skill checks from being "unusually flexible." It's 1st-level only and can make the creature look scary, awesome, or scary awesome at the DM's discretion. As it counts as the feat Aberration Blood (LoM 178) (which could instead grant the creature +4 racial bonus to Escape Artist skill checks, but the creature then has "slimy skin"--ew), it grants access to...

  • The aberrant feat Inhuman Vision (LoM 180) grants the creature darkvision 5 ft. per aberrant feat and a +1 bonus to Spot skill checks per aberrant feat.
  • The aberrant feat Scavenging Gullet (LoM 181) grants the creature a +4 racial bonus versus ingested poisons and diseases. More importantly, it grants the creature the ability to "gain nourishment from eating any organic material, despite its freshness or source." For a sensate, this is gold.
• The fighter and general feat Master of Mockery (Dragon #333 88) grants the creature the ability to make a Perform (comedy) skill check as a standard action. The check's target makes a Will saving throw (DC = the Perform (comedy) skill check's result). If the target fails, it's enraged, gaining a +2 bonus to attack rolls versus the creature, taking a -2 penalty to Armor Class, and attaking the creature "whenever able." Talk to the DM about the effect's duration.
• The tactical feat Combat Panache (PH2 93-4) grants the creature use of 3 tactical maneuvers that are wildly subpar or difficult to use but a a lot of fun. Two maneuvers actually require the creature to be hit and take damage before they can be used, and the other requires the creature to hit and inflict damage before it can be used. Nonetheless, they're flashy and fun.

When determining the price or a magic weapon or armor you look at the bonus it provides plus any increases from properties. So assuming that the Retaliation property was placed on a +1 suit of armor it would be costed as though it were a +3 suit of armor (9000gp + the cost of the masterwork suit of armor)

From the SRD (emphasis added):

In addition to an enhancement bonus, armor may have special abilities. Special abilities usually count as additional bonuses for determining the market value of an item, but do not improve AC. A suit of armor cannot have an effective bonus (enhancement plus special ability bonus equivalents) higher than +10. A suit of armor with a special ability must have at least a +1 enhancement bonus.