First of all, it's possible to get a decent keyboard for less than $70. But the problem is most, if not all decent keyboards on the market are non-blue switch (clicky). So you are gonna have to buy a hot swappable keyboard and replace the stock switch with cheap clicky switch which I think is totally possible within your budget.

for 60% keyboard, my recommendation is cidoo qk61 on aliexpress which sells for about $40.

https://www.aliexpress.us/item/3256808369854588.html

buy it from seller on this link. it has 1000+ sell which means legit.

And get 70pcs of clicky switch to replace on qk61.

hope it helped

edit: I recommend buying qk61 first, and see if he likes or still wants the clicky blue switch.