The phrase "there now exist" is correct and usable in written English.
You would use it to introduce a fact or a list of items. For example, "There now exist a variety of options for treating anxiety."
Fortunately for him, there now exist "three-dimensional printers" that, at a cost of a few hundred dollars, will convert one of the complicated surfaces he draws on his computer into something he can grasp.
For instance, you no longer need to be a Sith to display dark-side powers (as Adam Driver's Kylo Ren proved with merciless cruelty), and there now exist Jedi-aligned allies of the Resistance who have no capabilities themselves (Max Von Sydow's Lor San Tekka and Lupita Nyong'o's Maz Kanata).
Neither have I. Regardless, there now exist stretchy beer condoms for your beer bottles.
Diffusion limitations may lead to considerable loss in activities and selectivities There now exist many techniques to synthesize uniform pore sizes and pore networks.
As a result of our new measurements there now exist for both target elements a complete and consistent database for the production of noble gas isotopes.
Under MAR, inferences will be valid, and there now exist many methods for handling missing data under the assumption of MAR.
In the Ocean Village Apartments at the Shore in the Rockaways, there now exists a dividing line at the 10th floor.
This does not mean that there now exists a positive constitutional right to whatever sexual conduct anyone would like.
Green later agreed with him and said that there now existed a "much clearer legal framework" to accomplish this.
The world ran out of IPv4 addresses in July, making them increasingly valuable, and there now exists a market in what are effectively second-hand IP addresses.
One way that the invention of the chicken wing seems to have improved morale is that there now exists among Buffalonians a widespread commercial fantasy of hitting it rich by introducing Buffalo chicken wings to some virgin territory.
