There are dozens of free crypto exchange scripts on github and developing will never cost 150K.
first start indexing in the services of aggregators of crypto exchanges, then write. our exchange 5 march was 3 years old. we are integrated in all aggregators, our portal has never been turned off in three years, if the exchange is turned off for no reason, it immediately flies out of services for indexing crypto currencies such as coinmarketcap and coingecko
please do not write messages for no reason, and do not advertise your services