The problem is that there aren't any empty lots at that price in the newer towns. For the Immortal Dynasty Challenge, Metro has made accomodations for the lots that are available, but Pinstar hasn't published anything specific for new towns. I suppose it doesn't really matter because there's not a leader board or hall of fame for the legacy challenge and most players change the rules to suit themselves anyway.
That's a shame because half the fun of a Legacy (for me anyway) is that struggle to get over the poverty at the start!
For the Sims 2, the rule was that you had to move into an empty 5X5 lot, but some players found that their computers struggled to handle a lot that large. An accepted workaround (I believe Pinstar made it official, but I can't find proof of that) was to start on a smaller empty lot and use the family funds cheat to reduce your Sim's money to the traditional starting amount.
So I think that's the answer for anybody wanting to a legacy in Bridgeport. Pick an empty lot, and use familyfunds to give your Sim just $1,300 in disposable cash (there's a thread in miscellaneous help about how the familyfunds cheat works). Alternatively, I suppose you could give your founder the 'good' trait and donate your extra money--it'll give you a positive moodlet, but that's all the benefit. Any other ways of getting rid of your cash without benefitting from it?
Talking about moodlets, you should find an empty lot that gives the beautiful vista moodlet. That's one of the nice things about the legacy lot in Sunset Valley.