In Frankfurt, you can call Benny Perl. He is driver who knows the place and can take you to kevarim etc... call or whatsapp +491776136137
In kerestir you can stay at Reb Shayaleh's guesthouse (I think they charge $70 a night, free food) call or whatsapp 347-370-2556
From BUD, you can get a pretty cheap ticket (sometimes $27 plus luggage and everything else) on Wizzair to TLV. I think there are some kevarim there...