Please - -
Spend the time and money necessary to get a decent leather holster for that nice little pistol. Yep, for a 90%+ 1908, $200 is pure theft.
Count your blessings, and treat the old gun well. You've already laid out a fair amount of cash on the ivory polymet stocks, so give it equal respect in the holster area.
Don't use a one-size-fits-none nylon holster. The soft, floopy ones are just an insult to a nice, classic piece such as that Colt Pocket Auto. The firmer nylon items are almost like using sandpaper on the finish. And please, don't even TRY fitting it into a molded plastic or Kydex holster. It's even worse than the nylon
I suggest that, pending being able to have a custom holster built, you take the little pistol to the various gun shows in your area. Make a slow browse around the tables. There are always a few guys who specialize in used leather gear. Some go to the pawn shops and gun shops that accept trade-ins and buy up the old hosters for a few cents on the dollar. I've found some very nice items for five or ten bucks.
Put out the word at your local pawnbrokers and gun shops, too. You might get lucky that way.
Some other suggestions - -
I have at least one holster made for a Walther PP which fits my 1908 well. You just need to try - - Most PP leather is fitted too closely at the front of the slide to accept the broader snout of the 1908.
Look for a holster made for the Kahr 9mm. It'll probably be a bit wide in the slide area, though.
Ask your gunshops if they have a holster designated for the recent model Colt .380 Government Model. I've never tried this for fit with a 1908, but the sizes seem compatable.
Check out the Bianchi #105 belt slide - - It'll at least keep the pistol at her side while at the range, and it is fully lined, to protect the finish.
Congratulations to your wife on her nice pistol. Best of luck on your holster quest.
Johnny