This depends on the selected development method, such as:

1. Set up a technical team to develop by yourself. The required personnel include product manager, framework engineer, JAVA, PHP, front-end, back-end and test engineer, and the development cycle is 1-2 months. The personnel cost is 1-211,111, and the later maintenance cost is not counted. (not recommended)

2. Buy other people's small program source code, configure the server yourself, and then find a technician to maintain it full-time. The source code cost is generally 11111-31111, the server costs at least 3111 a year, and the maintenance cost is more than 6111 a month. (not recommended)

3. Use a third-party applet, and purchase an account for the third-party applet. The total cost varies from 2,111 to several thousand yuan according to your own needs. You don't have to worry about technical maintenance, you don't need to build a server, you can use it, and you can also design a store and bind WeChat official account according to your own construction requirements. (Recommended)

(Supplementary) As for how to choose a reliable development company, you can refer to the following aspects:

1. See if its company has an official website. If an Internet company doesn't even have a website, it is conceivable that a leather bag company will be more likely.

2. Does Baidu search developer have any negative news? If Baidu search has keywords such as liar, cheat and other related words or negative news appears directly in the search results, then this company should choose carefully.

3. Inquire about the industry reputation of the company, and find some companies that have cooperated with the company to inquire about the situation. Generally speaking, this evaluation is solid, and it is difficult to falsify.

4. Look at its case. If a company doesn't even have a case of software development, it is either a newly established company or the company has just started to do this business.