Boris FX Titler Studio is $199 for the perpetual license, or $25 a month for subscription. It works in Vegas Pro well.
If you want super cheap though, Bluff Titler is something like $62 or so (not good at converting pounds to dollars here), but I think it is a standalone software.
@ChasMcBorisFX Titler Studio and Prodad Heroglyph are the only other two options available as a Vegas Plugin.... Unfortunately these options are not cheap.
Bluff Titler isn't a plugin, but standalone. As @Steve_Rhoden said, the 3rd party title software is not cheap. You can wait for sales on TP7, or monitor Magix Movie Studio to see if they offer TP7 with their software on a sale. Installing TP7 or any NBFX plugin usually installs in Vegas. Also consider this, I can not get TP7 to work at all (stalls at loading the Library) since 22.5.1 driver. I am now using 24.2.1 graphics driver. If I want to use TP, I have to go back to that GPU driver.
For the last several years, BorisFX has had a 25% off one product sale in late April - the sale is fairly much the same as the Black Friday sale.
While I have no idea if that sale will occur this coming April, you might consider getting the trial version of Title Studio and, if you like it, purchase it in late April if the BorisFX April sale takes place this year.
Or do what Reyfox suggests and wait to see if Magix Movie Studio offers a package including either NBFX Titler Pro or NBFX TotalFX (which includes Titler Pro). I think that a package with TotalFX has been offered twice in the last 2 years.
Well... I have tried and Boris and NewBlew and went to make titles in AfterEffects. But there is also an option to use HitFilm (or Vegas Post) and make titles in it (there are some tutorials and ready made projects for Hitfilm).