Where to spend gems

If you've ever thought where should I spend my gems, you are at the right place. In this guide I talk about the best usage of gems in Diggy's Adventure.
The following list is sorted in order of priority and is based on my own thoughts and calculations.

1. Gem Carts

Builder Icon

Every region has a gem cart that is very much worth the value.
If you're just starting out, you'll probably need this extra storage after a few levels so you can get to play longer.
Even in higher regions, the capacity of the gem carts is more than the average equipments for that region, so it's a must buy.
No other equipments that sell for gems are as good as these and I don't recommend buying any other with gems

2. Professor Switch System

Professor's Switch System

You may not need this in the beginning of Egypt but after scandinavia, this is a really useful tool.
It allows you to have 2 sets of camps and you can switch between them in 1 click. Use the day mode with more regeneration equipments when you are free to play every hour to two and the night mode with more storage equipments when you are at work or going to bed so you have more energy after work or in the morning.

3. Old Stories

Old Stories

Old stories are another good way to spend the gems, you get something to play and the equipments of that event.
Christmas 2015 in the best story to purchase and gives a lot of gems back and has amazing equipment so if you haven't purchased this, go for it (recommended for egypt, scandinavia, china if you have over 200k coins)
If you're in higher regions (over china), the non-vintage events are better for you since the equipments in vintage events won't be useful for you.

4. Energy Saver & Experience Booster

Passive Boosters

With these boosters, you get a certain effect like free energy while digging or double experience.
At level 10, you can get energy back for 3% of the tiles and double experience on 10% of the tiles.
The best part is these last for life. Equipments you buy might become obsolete in the next region or two but the boosters last forever. So if you plan to play for long, go for these!
I find the energy saver worth more so I recommend buying it first upto level 10 before you start buying energy booster.

5. Energy Boxes / Tiered Offers

If you're at the beginning of your region, you can try your luck with the equipment boxes or purchase the tiered offers.
These aren't available all the time, only occasionally released maybe once in 2-3 months for a week.
Don't go for these at the end of region as the equipment won't be worth it in the next region you are about to enter.

Anything else?

What not to spend gems on

There are also a few things you should avoid spending your precious gems on, which in my opinion are: