Gengar advice for a fool, thanks in advance.

[TheInquisitiveMug]

TL:DR I have a Gastly with IVs 15/7/31/31/31/13 and a Modest Nature.  Assuming I'm poke-money broke and this is the last Gastly ("Lastly") I'll have for a while, is it worth breeding with an IVs 8/25/2/31/31/31 Gastly for the perfect Speed IV  for a 4 x 31 IV spread (x/x/31/31/31/31) and sacrificing that lucky Modest nature for a random egg nature?

Still Long ; Maybe Read? - I had a few lucky catches early post-Hoenn E4 getting two 1 x 31 IV Dittos for Def and Sp.Def, respectively and two 31 Sp.Att IV Gastly's from Sprout Tower of all places.  Like in the first five caught of either species.  Bred them for a 15/7/31/31/31/13 Gastly.
Laboring under the ignorant delusion that a Gastly with a hidden ability diamond-thingy and Levitate meant that I could have a Gengar with Levitate like the good ol' Gen IV days, I bought early and blew $120,000 on the above 8/25/2/31/31/31 to hopefully get a sweet 4 perfect IV Levitating Gengar and just breed that sweet diamond nature down the way.
...No regrets until I got that Modest Nature 15/7/31/31/31/13 and found out that Levitating Gengar isn't a thing.  Womp womp, drum rimshot, audience laughter, Loony Tunes cane pulling me off stage of the Apollo.
As far as cash goes, I've still got the better parts of Johto and Kanto to go, Sinnoh and Unova untouched, and I'm free as a bird in Hoeen for everything but an Elite Four rematch cycle (they're all Lvl.100 on rematch, right?) so I'm not gonna be flush with cash for another breeding investment for a hot minute,

What would you cats do?  Thanks in advance.

Edited December 27, 2023 by TheInquisitiveMug
mistyped the speed IVs for Modest Gastly

[TheInquisitiveMug]

Whoops, had a 31 for Modest Gastly's speed instead of a 13.  Dyscalculia got me.  Sorry for any confusion.

[Ramallero]

If you are broke and really can't wait to play pvp, don't go for 5x31 mons.. just use 3x28 2x31+ nature

Also idk what team do you have in mind (and what gengar build are you going for), but Timid > Modest most of the time.