Can someone help me understand money line betting?

[wild card]

Hi everyone. I have been trying to wrap my head around the following concept for a couple of weeks now, however I'm not sure if I have the right answer. Let's say that I have a friend who looses most of his bets and I decide that I want to fade his picks all year long. And let's say that we are working with $100 units. If he goes to a bookie and places a bet on team A at -130 and he lays $130 to win $100 (thus insuring that he wins 1 unit), what bet would I have to place in order to make THE EXACT OPPOSITE BET as him?
Option 1-(I believe that this is called base betting) Let's say that team B is priced at +120. Would that mean that I would place $100 to win $120?
option 2-(also try to win 1 unit) Or am I suppose to try to win a unit also and risk $83 in to win $100?
option 3-(match the price with the dollar amount) or do I lay down $120 in order to win $144?

I believe that it's option 1 but of course I'm not sure.
Thanks for your time, any explanation would be helpful and appreciated.

[subs]

there is no set rule here because ur edge is not defined but IMO, to win the same amount.

100/120=0.83

if u bet $83 u will win approx. $100.

BTW it is almost exactly as difficult to pick losers as to pick winners and fading ur friends plays is unlikely to overcome the vig.

this strat gets thrown around almost every month or so and doesn't work.

GL

[8ArIvd5]

Op 3 would have you bet 130 to win 156.

But like subs said, you'd have to check his win% to see if this strategy would work

[subs]

why don't u book his action and maybe offer him rebate on his loses?