There are many favorable aspects to buying an existing business such as an existing customer base, a team of employees and drastic reduction in startup costs. You may be able to jump start your cash flow immediately because of existing inventory and receivables.
But there are also some downsides to buying an existing business. Purchasing cost may be much higher than the cost of starting a new business exactly because the initial business concept, customer base, brand and other fundamental work has already been done. Also, be aware of hidden problems associated with the business (like debts the business is owed that you may not be able to collect).