Business/IT Consultant by profession - Is there a market for small business consultancy?

As the title suggests, I’m a consultant for one of the UK’s big 4 consulting firms and I’m looking for a way to both develop my consultancy skills but also earn some additional income.I wanted to try and offer some of my knowledge and skills to smaller businesses, giving some consultancy on their current business process, where they could save time and money and increase the available people hours available to them.My question is how would I go about charging a high enough price to make it worth my while while also being conscious of the fact that smaller businesses may not have the money to be able to afford traditional consultancy fees?I’d also like to try and build up a monthly income through this so I’m thinking a payment plan over X amount of months rather than a hourly fee?I’d be keen to hear some peoples thoughts. see hubwealthy.com/wealthy