I'd disagree about saving for Mona. Yes I agree she is brilliant but she is also very expensive for a lot of players and regularly banned. There are much more economical uses for 70k for someone still missing a large portion of the collection.
Absolutely get Waller. He's the next best option and also super affordable. Desmond is fine instead of Edd Cr... in fact I use Desmond over Edd Cr willingly most of the time. Spiaghi should be used of course. That leaves you with one spot for a half deck...Angelo is good, but you can also use Ivy extremely inexpensively.
You're left with a low-star, defensive half deck strong at low pill battles - this leaves you a lot of room to pack a punch with your other half.
"Elo Montana without Mona is crazy...
It would be weak..."
Lol no. Whilst that statement would of been true in the past, Montana aren't all that weak without her. Desmond/Edd Cr, Waller, Spaighi and Angelo make for a genre at half deck albeit low on damage. Desmond destroys All Stars and Pussycats whilst Waller is probably the best 3* fork in ELO next to Lola. Spaighi and Angeli offer amazing utility for four stars.
Bottom line: Montana are good for walling purposes but lack the damage to be played as much as they used to be.
I dint say it's Impossible to play with out mona
However if u want to make best of them in elo, u need mona..
But JO3SHMO is right... For a person who lacks major portion of collection it's not wise to save up a lot of clints for a card that is banned regularly on votes :$
They're great, but other cards in their star category outclass them by far. For your 3* choice, go for Waller primarily. Mona is great, but overpriced, and you saving up for her is sort of like buying 2 Edd's anyway, and you're clearly on a budget.
For your 4*'s, Desmond is your best bet as stated. Some people also like Vermaire, but he is nowhere near Desmond's level it terms of solidity. Then you're left with Spiaghi and Angelo, who are both so much better than Ace due to the utility they provide.
tl;dr, basically what Pingerz said.