this is assuming you can drop gems on that gacha like the plague....
if you do the 100 pulls on the 10 draw alone, that's 100k gems per day...
assuming you do this all week, you'll spend 700k gems so from gem quests alone (which appear daily, along with all day sunday), you'll need to spam enough half elixirs to make up those 700k gems you spent...
depending on your luck, you might break even, you might not... i don't really pull more than 10 (sometimes i pull only 2) and i spend less than 10 in half elixirs to make up those 100k gems i spent... if it's the gem quest that's up for only 30 mins...
you more or less have to hope you pull enough half elixirs to make that up, cause outside of gem gacha, you'll have to rely on advent events to make that up (and you should have no less than 40 from the rematches we just had if you went after those).
the half elixir rate from the gem gacha is better than you'd think, but luck can still give you a big middle finger and not give many...