"Broke" 18 month old horse for sale

[RhndLev@cs.com]

The man who bred my TWH mare, who I adore BTW, called and offered to sell me 
her full sister.  This full sister is a BEAUTIFUL mare.  My mare is handsome, 
her sister is just Arabian level pretty.  The filly is naturally gaited and 
the price is reasonable.  The big hesitation I am having is that this guy 
says she's fully broke to ride and she's 18 months old.  I had expressed an 
interest in buying this filly last fall and the man said he was going to keep 
her and show her under saddle this year.  I told him that I was waiting until 
my colt was three years old to start him under saddle and he made fun of me.  
I even offered more money for the filly last year if he DIDN'T start her 
under saddle.  Now, he's offering her to me for less money than I offered 
before.  [Go figure.]  Anyway, now I'm not sure I want the filly because I'm 
really concerned about the long term repercussions of her having been started 
this early.  Any thoughts?  I know to get X-rays of her legs, but would any 
damage show up at this stage?  I just don't want a repeat of my first horse 
where the damage from being started so early and used so hard did not show up 
until after I'd had him for over a year.

Rhonda and Special