Everything you save is a death counter - level, money, class, upgrades. You pick the counters your triggers already use.
For each one you set a range and a precision, and those two decide the length. Levels 1-100 cost almost nothing; money up to 300 million stored to the exact unit costs a lot. Store money in steps of 10,000 and it collapses.
The player types this code by hand, so shorter is better. Giving up a little precision to save two or three characters is usually the right trade.
Changing the set of stored values later invalidates every code already issued - that includes adding a field or widening a range. Leave yourself headroom at the start.