Key fob or other issues

[roseschulstadt64]

We bought 2000 lexus gs300 used non dealer and sometimes car will not start, red dot anti theft still blinking.  Yes, replaced fob battery but no luck.  It's odd, starts when it wants to recognize key.  So money big issue and I'm over the struggle anymore.   I need help.  I just need help.  I had to file disability and I'm angry about that, just so u know I am not asking for a pity party just not sure where to go