If you're at $100 or less,you're OK,I think,as far as price goes in terms of re-sale of parts.The tanks don't look too dented and those Monarks
are becoming more desirable as Schwinn prices keep climbing ever higher.As for a "builder" for your personal use,I'd suppose whatever you are comfortable with spending is what you'd have to decide.The pleasure of the build,the hunt for parts & goodies,that first ride or bar hop,
your pals eyeball'in it for the first time...PRICELESS!!! To paraphrase Ian Gillian (DEEP PURPLE) "Its not the kill,its the thrill of the chase".
Good luck...keep us posted...just so you know,that is a mid-weight frame (I have one just like it,mine's a '58) so keep that in mind while you're choosing your wheel/tire/fender combination...P 8)