The exact limits for opening a new deal depend on your past deals, your verification tier, jurisdiction of the selected shop, shop's own limits, market conditions, and other factors. You can always see exact limits when starting a new deal in your LoCoins account.
Limits for a specific Tier can be tied to a day, week, month or lifetime. Exact limits depend on the applicable jurisdiction. LoCoins may change the limits over time to adjust to evolving legislation in the field of cryptocurrencies.