22. Is there a limit on in-kind donations to candidates?

12.3(2) & 12.3(4) Political Parties Act, the amended version of law in force from 23.03.2015, No. RT I 1994, 40, 654.

The donation limit is common for cash and in-kind donations. However, candidate can use personal property without limitation:

The sources of funding of the election campaign of a single candidate include:
1) donations made on the terms and conditions laid down in this Act;
2) personal property of the single candidate.
Source: § 5.2(3)

As according to 5.2(5), the section 12.3(4) applies to single candidates, so yes, there is a limit for non-monetary donations.

Other in-kind donations as special services or discounts are not allowed.

12.3 (2) A donation that does not comply with the terms and conditions laid down in subsection (1) of this section is prohibited. Above all, the following is prohibited:
[...]
3) the transfer or the granting of use of goods, services or proprietary rights to a political party on conditions not available to other persons;
4) release from ordinary binding duties or obligations;
5) waiver of claims against a political party;